A 28 year old man form Ohio, diagnosed with AIDS, developed chest pain. After a short period
of time he also developed severe headaches with dizziness. In his free time he explored caves.
His physician ordered a sputum culture and spinal tap and both were positive for a yeast like
fungus. These finding are most consistent with infection by:
Candida albicans
Coccidiodes immitis
Cryptococcus neoformans
Histoplasma capsulatum correct answers Histoplasma capsulatum
A patient is diagnosed with coccidioidomycosis. This infection can be classified as:
subcutaneous.
systemic.
opportunistic.
superficial. correct answers systemic.
Which statement best describes antigenic variation of a parasite?
Answers:
Parasites can change their antigens or create novel antigens.
Parasites do not have any surface antigens.
Parasites are ingested by macrophages, and antigens are denatured.
Parasites have similar host antigens. correct answers Parasites can change their antigens or create
novel antigens.
The most sensitive test for the initial diagnosis of cryptococcal disease is:
Answers:
India ink
Gram stain
Cryptococcal antigen
Giemsa stain correct answers Cryptococcal antigen
A patient has been diagnosed with tapeworm. Identify the type of parasitic organism involved.
Answers:
Protozoa
Helminth
Ectoparasite
Host correct answers Helminth
TORCH refers to a group of tests used to diagnose newborns and certain pregnant women for
organisms that cause congenital infections such as: toxoplasmosis, other infections, rubella,
cytomegalovirus, herpes simplex virus
Answers:
True
False correct answers True
,The presence of anti-H antibodies indicates which of the following?
Answers:
A previous infection with Coccidiodes immitis
A previous infection with Histoplasma capsulatum
An active infection with Cryptococcus neoformans
A active infection with Histoplasma capsulatum correct answers A active infection with
Histoplasma capsulatum
A parasite accesses a target cell in a host, thus hiding its antigens from the host's immune system.
This survival strategy is known as:
Answers:
antigenic mimicry.
antigenic concealment.
shedding. correct answers antigenic concealment.
Which of the following scenarios presents the greatest risk for coccidioidomycosis?
Answers:
Missouri cattle rancher
Wyoming rabbit rancher
Central Valley California migrant worker
Pregnant woman with several housecats correct answers Central Valley California migrant
worker
Which of the following is indicative of a parasitic infection
Increased IgA levels
Increased IgG levels
Increased IgM levels
Increased IgE levels correct answers Increased IgE levels
A limiting factor in reliably being able to detect anti-fungal antibodies in an acute infection is:
Answers:
the lack of humoral response to fungal agents caused by immune suppression
current assays lack specificity
antibodies are not normally formed against most fungi
antibodies tend to remain at low titers as a mycosis develops correct answers the lack of humoral
response to fungal agents caused by immune suppression
Histoplasma capsulatum
Answers:
Can cause disseminated disease in immunocompromised people
usually causes a subclinical infection or mild flulike disease
Is associated with bird droppings particularly bat guano
, all of the above correct answers all of the above
Eosinophilia and an increase in which immunoglobulin play a role in the defense against
parasites?
Answers:
IgA
IgD
IgE
IgG correct answers IgE
Compared with a host's response to the mumps virus, overcoming a parasitic infection is more
difficult for the host because of which of the following characteristics of parasites?
Answers:
Large size
complex antigenic structures
elaborate life cycle
all of the above correct answers all of the above
Which of the following is indicative of a recent infection with Toxoplasma gondii?
Answers:
Anti-toxoplasma IgE
Anti-toxoplasma IgM and low avidity anti-toxoplasma IgG
Anti-toxoplasma IgM and high avidity anti-toxoplasma IgG correct answers Anti-toxoplasma
IgM and low avidity anti-toxoplasma IgG
Which of the following conditions is best detected via serological testing?
Answers:
Ascariasis
Lyme disease
Malaria
Toxoplasmosis correct answers Toxoplasmosis
Low avidity IgG antibody
Answers:
indicates that an infection that occurred in the distant past
never occurs because low avidity antibody is IgM
is replaced rapidly by high affinity antibody and so is never seen in diagnostics tests
indicates a recent infection correct answers indicates a recent infection
The parasitic infection Cryptosporidium parvum is